All 4 of the Wagners were charged with burglary, but it was assumed it was in the context of breaking into the victims' homes for the purpose of killing them and for the theft of security cameras and equipment. Was anything else stolen? Did they question Chris Sr. and Gary about the location of all the cameras before killing them?
ETA: WRT bullets found under the mobile home (new information), could those have come from shooting one of the victims while they were lying on the floor? I assume those subfloors are plywood or particleboard.
https://mobilehomeliving.org/how-to-replace-flooring-in-a-mobile-home/
Shells outdoors on the front porch could have come when they shot at Chris Sr. when he opened the door. He may have seen them outside and thought they were coming to fight again, so he may have opened the door without a weapon.
As for the rest, its long been the consensus here that Chris Sr. ran into a bedroom, possibly to retrieve a weapon, and was shot through that door.
Considering how much of a fight he put up, he came close to preventing the massacre. Sad.